Lens-grinding apparatus



I K. v. HILL. ET AL LENS GRINDI-NG APPARATUS Filed April 18, 1922INVENTOR EMA/[771M H/LL. 06141? 0. T/LLYER ATTORNEYS Patented Nov. 4,1924.

STATES ?ATENT OFFICE.

KENNETH V. HILL AND EDGAR D. TILLYEB, OF SOUTHBRIDGE, MASSACHUSETTS, AS-

SIGNORS TO AMERICAN OPTICAL COMPANY, OF." SO'UTHBRIDGE, MASSACHUSETTS, AVOLUNTARY ASSOCIATION OF MASSACHUSETTS.

LENS-GRINDING APPARATUS.

Application filed April 18, 1922. Serial No. 554,762.

I 0 all whom it may concern Be it known that we, KENNETH V. HILL andEDGAR D. TILLYER, citizens of the United States, residing atSouthbridge, in the county of Worcester and State of Massachusetts, haveinvented certain new and useful Improvements in Lens-Grinding Apparatus,of which the following is a specification. V

This invention relates to new and useful improvements in feed controlsfor lens grinding machines, and more particularly to a thermostaticallyoperated control whereby to regulate the control of rouge or otherabrasive material with respect to the temperature during the grindingoperation.

It is a well known fact that during the grinding of lenses in thepresent method the friction between the polishing block and the lens ina great many instances provides considerable high temperature grindingdue to the friction between the lens and polisher, especially when thesupply of rouge or other abrasive material has become nearly exhaustedduring the grinding operation.

It is, therefore, another object of our invention to provide meanswhereby when the temperature caused by the friction as set forth abovereaches a certain height a supply of rouge or other abrasive materialwill be automatically fed between the polishing block and the lens.

A further object of the invention is the provision of an automatic feedcontrol for lens grinding or polishing machines wherein an electriccontrol is actuated through a thermostatic member, which in itself isactuated through the rise and fall of temperature due to the frictionduring the grinding or polishing operation, whereby when the temperaturerises to a certain degree, rouge or other abrasive materials will be fedonto the work and eliminate the unnecessary friction andhightemperature.

' Other objects and advantages of our improved construction should bereadily'apparent by reference to the following specification taken inconnection with the accompanying drawings, and it will be understoodthat we may make anymodifications in the specific details ofconstruction shown and described the scope of the appended duringtheclaims without departing from or exceeding the spirit of ourinvention.

Figure I represents a semi-diagrammatic sectional view illustrating oneembodiment of our invention.

Figure II represents a similar view showing an electrically controlledform.

Figure III is a similar view illustrating the employment of a thermocouple for controlling the abrasive discharge.

In carrying out our invention we use any well known form of grinding orpolishing machine, which includes a lens supporting head 1, amovablepolishing block 2, which is controlled through the crank 3. The block 1-is provided with a chamber 4, and arranged within this chamber is athermostatic bar 5 which may be of any commercial dual bar used for thispurpose, the said bar being rigidly connected at one end of the chamber,as shown at 6, the other end of the bar being free to move in accordancewith the temperature of the chamber.

Attention is called to the fact that this chamber 4 is arranged directlybeneath the upper face of the block 1, whereby the high or lowtemperature reached during the grinding or polishing operation willreadily control the movements of the bar 5.

The feeding operation, which is connected with the bar 5, includes aninlet pipe 7 having a feed nozzle 8 at its outer end, and furtherprovided with a valve 9 to control the outlet of the abrasive materialthrough the nozzle. The valve is provided with an arm 10 and pivotallyconnected with the outer end of. this arm is a link member 11, the lowerend of which is pivotally connected to a movable bar 12. The bar 12 ispreferably pivoted as at 13 and connected at one end by means of a link14 to the free end of the thermostat bar 5. From this it will beapparent that movement on the part of the bar 5 will readily impart arocking movement to the lever 12 for opening or closing the valve 9. Inthe present arrangement which we have 1llust-rated upward movement onthe part of the bar 5'will close the valve, while downward movement willopen the valve. Thus when the temperature within the chamber 4 reaches acertain height the bar 5 will move downwardly actuating the lever 11 foropening the valve 9 and releasing rouge and water or other similarabrasive material from the nozzle 8, where the same is conveyedonto thework being carried out.

In FigureII, we have illustrated a modified form of the inventionwherein a suitable electric circuit forms connection'b'etween thethermostat control and the feed control. In this form of the invention acontact member is carried by the bar 5' adapted to engage the contactpoint 16 upon downward movement on the part of the bar 5, and as thiscontact point 16 is connected through the solenoid 17,, to the valve 18,the valve 18 will be actuated to open communication in the inlet pipe 19and the nozzle 8", whereby to inject a'supp'ly of water and rouge orother abrasive material onto the work;

. Inthis' form of the invention the regular commercial dual bar is used,as in the main form of the invention, and is rigidly connected at 20 andthe other or free end of the liar being provided with the contact 15which upon downward movement ofthe bar will en age the contact 16 andcomplete. a. cii'euit or actuating the va-lv'e 18. Upon upwvai'd'moven-ien't of the bar 5" the valve membl 18 will be actuated throughthe solenoid 17 to close communicationbetween the inlet pipe 1 9 and thenozzle 8.

In Figui-elll we have illustrated another form of the invention whereinwe use commercial thermo-coupling and attach the same to the underfaceof the lens support ing block, as indicated at 21, and connect the*sar'neflwit'h an ordinary. temperature indieater 22', saidindicatorbeing set whereby to ,niake or break a circuit at a certaintemperature. Suitable connections are provided be-- erate to close thevalve is and cut oil the supply of abrasive material. From this it'wlillbe apparent that when the amount of friction between the lenspolishing block and thelens becomes sufiicient to pr'o'd'i'ic'e atemp'erature of a certain degree, means is operpated throughthermostatic control, wherebyto su pl a sufficient "amount or water andr uge or other abrasive materialior reducing' the temperature andeliminate the fric- 'itio h eaueea by the absence or the abrasivematerial so that the work can be readily carion. without the ne'ees'sityof stopping win s has heretofore been nneipal ly due' to the", lag'liofpro er feeding of the: abrasive material on the work.

, Ween e 1. Lens grinding apparatus including a lens support, fluidsupplying means adjacent "the support is heated.

2. Lens polishing apparatus including abradant supplylng means and athermostatic control for regulating the discharge of abradant therefrom.

3. In lens grinding mechanism, the combinationwith a lens holder, of anabradant supply device adjacent saidholder and heat operated meansbetween the holder and said supplying device for increasing the supplyof abradan-t therefrom as the temperature of a lens on the holder israised by the grinding action.

4. Lens grinding apparatus of the character described comprising a lenssupport, a. lens surfacing tool arranged inproximity to.

the support, means to rotate the. lenssurfac- 111g tool, an abradantYsupply; receptacle arranged in proximity to the lens support, a

supply pipe extending from the said recepta cle so as to overlie thelens support, a valve in the supply pipe, and a thermostat connectedbetween the lens support and the valve whereby to openand close thesupply pipe valve atpredetermined temperatures.-

5. Lens grinding apparatus of the character described comprising a lenssupport, a lens surfacing tool arranged in proximity to the support,means to rotate the lens surfacing tool, an abradant supply receptaclearranged in proximity to the lens support, a supply pipe extending fromthe said recep tacle so as to overlie the lens support,- a valve in thesupply pipe, a heat responsive element carried by the lens support, andlink means connected between the valve and the heat: responsive meanswhereby to open and close the valve at predeterminedtemperatures; 6. Alens polishing apparatus of the character described comprising .a lenssupport having a recess formed in the lowerface thereof, a lens grindingtool arraned proximity to thefsu-pportand adaptec to'be rotated, anabradant supply device, an'outlet pipeoarrie'd thereby adapted tooverliethe lens support, a control valve: arranged within the supply pipe, aheat respdns ive member arranged in the recess in said lens support insuch position as tqbeaifected by the heat generated between the contactof the lens and grinding toohandlink means connected between the controlvalve andheat responsive means whereby to open and c ose the valveatpredeterm-ined temperatures. I

EDGAR 11- TILLYER.

